Determining exposure time - film under enlarger

[ivansbacon]

How do I determine exposure time for film under my enlarger? I want to expose a 35mm neg onto 4x5 film. I have a Minolta IV exposure meter.

 

[Jim Jones]

One way is to do test exposures. Paper often has the equivalent if somewhat less than ISO-10. Adjust your exposure accordingly. You will lose contrast unless you are using very contrasty film such as litho or Tech Pan.

 

[Konical]

Good Evening,

Jim has summed it up fairly well. A couple of sheets of film with stepped exposures should get you into the ballpark. If you're lucky enough to use an enlarger with brightness control (e.g. Beseler Resistrol or something similar) dial it back as far as possible; otherwise, a fairly heavy ND filter might come in handy.

Konical

 

[Donald Miller]

Take an incident meter reading with you Minolta meter IV and determine your exposure based upon the EV reading and the film that you are printing on.

As others have mentioned, you will likely have very short exposures...possibly beyond the precision of your enlargiing timer. As the exposure becomes very short, any improper exposure discrepencies will become proportionately greater. Also you might remember reciprocity considerations if you are able to get exposure times up into the one second range.

I would think that you are probably going to need to add neutral density to the light path depending, of course on the film that you are exposing.

By way of information, in making BTZS film tests using 100 ASA film, I normally shoot for an EV of 4, on the baseboard, to get the times below reciporocity range and also reasonably long. Exposures seem to work the best when they are in the 1/2 second to .8 second range.

 

[ivansbacon]

Thanks for the replies. First I know nothing about the film GAF 2863 mid seventies. speed, EV,dev times or ? . i did run a sheet through the fix and it looks good and clear, I think its b/w. Eventually I would like to use other films ( ortho as well as pan or ? )
I did a test in tenth of a second exposures but I put the film on my white easel and all I got was a neg with no image but an overall medium density to it do to the light reflecting off the easel, 80 mm lens at f22 I will have to get some black mat board to put on the easel. I have not been able to get back in the darkroom again. I know nothing of EV numbers and how that info can be used. I did find a manual for my meter thanks to this very helpful forum. I know that I need to do a test with each film but I thought I could use my meter to get within a stop or so and then test in ¼ stop increments and adjust dev time for contrast control. Thanks again for your time and info